The real reason for the "plateau" in cooking BBQ
I had to delete my eloquent writing on NC BBQ because of space limitations, but in any event, that is not what my question is about. As I go about cooking my BBQ and reading about cooking BBQ, I read a lot about "the plateau," and that is the focus of my question.
According to the folk wisdom, pork shoulder will plateau at anywhere from 170-190 degrees Fahrenheit. Again according to the folk wisdom, at this temperature, the heat from the charcoal is rendering the fat, or connective tissue, or whatever, and once this happens we should just be patient and allow this "low-and-slow" cooking to happen. The promised reward is perfect BBQ.
But I've been thinking about this premise, and thinking about my actual experience, and I am having some doubts. In the first place, what I've seen with my own cooks is that when I raise the charcoal temp (with my Stoker), the meat temp raises as well. The meat temp trails the ambient temp, but if one moves up or down, the other does the same. If the energy was strictly going to rendering, you wouldn't expect that.
Secondly, I've been thinking about wet-bulb versus dry-bulb temperature. And what I'm wondering, then, is if the plateau is just the dessication of the outer layer of meat so that the effective temperature is closer to the dry-bulb than the wet-bulb.
For example, if you're cooking at sea level in a 250-degree cooker with 25% humidity, the wet-bulb temperature will be only 185 degrees. So if you stick a shoulder in there, it will not get any hotter than 185 degrees until all the water evaporates from the surface, and then it will start climbing towards 250.
I'm almost out of characters, but Kenji, as my favorite food writer/scientist and fellow lover of pork, I would expect you to rise to the challenge. Is the "plateau" in BBQ simply the difference between the wet-bulb and dry-bulb temperatures before the outer later of meat is dessicated, or is there something more going on?
I look forward to your report.